In the assembly of turbine blades and vanes, it is known in the art to mount or secure an inner wall member of air foil cross-section within an outer wall member also having an air foil cross-section. Typically, the inner wall member or insert includes a radially outwardly directed collar at one end of the insert that is brazed or otherwise joined to surfaces of the outer wall member. The inner wall member may include dimples or other protuberance structures extending outwardly from an outer surface of the insert that align or register the insert relative to an inner surface of the outer wall member. The assembled turbine component includes one or more air chambers formed between the outer and inner wall members that are used to cool the outer wall member during operation of the turbine engine.
Typically, compressed air from a compressor of the turbine engine is delivered to one or more inner chambers of the inner wall member or insert. The compressed air discharges through apertures formed through the inner wall member as a series of high velocity air jets that impinge upon and cool the inner surfaces of the outer wall member. Air is also discharged through apertures formed through the outer wall member to provide a cooling air film that travels over the outer surfaces of the outer wall member from the leading edge to the trailing edge. In this way, the turbine component is able to survive in the hot gas environment of the turbine engine without structural damage.
Notwithstanding advances made in the manufacture of turbine blades and vanes having an inner wall member or insert mounted or secured within an outer wall member, there is still a need for an improved joint for turbine components that provides a strong and reliable connection between the outer and inner wall members during operation of the turbine engine.